Note 11 - Derivative Financial Instruments - Fair Value of Swaps Recognized in Accrued Liabilities and in Other Comprehensive Income (Details) - USD ($) $ in Thousands	6 Months Ended
	Dec. 31, 2020	Jun. 30, 2020
Interest Rate Swap Effective December 19, 2015 [Member]
Notional Amount	$ 25,000
Fixed Rate	1.88%
Maturity	Apr. 24, 2022
Fair Value, Liability	$ (592)	$ (815)
Interest Rate Swap Effective May 24, 2017 Number One [Member]
Notional Amount	$ 25,000
Fixed Rate	2.83%
Maturity	Aug. 06, 2023
Fair Value, Liability	$ (1,812)	(2,167)
Interest Rate Swap Effective May 24, 2017 Number Two [Member]
Notional Amount	$ 100,000
Fixed Rate	0.91%
Maturity	Mar. 23, 2025
Fair Value, Liability	$ (2,435)	(2,485)
Interest Rate Swap Effective August 6, 2018 [Member]
Notional Amount	$ 25,000
Fixed Rate	0.88%
Maturity	Apr. 24, 2025
Fair Value, Liability	$ (577)	(585)
Interest Rate Swap Effective March 23, 2020 [Member]
Notional Amount	$ 25,000
Fixed Rate	0.91%
Maturity	Mar. 24, 2025
Fair Value, Liability	$ (603)	(615)
Interest Rate Swap Effective April 24, 2020 [Member]
Fair Value, Liability	$ (6,019)	$ (6,667)